The respirator humidifiers used hitherto have, in general, active humidifying systems, with heated evaporating chambers, via which the breathing gas to be humidified is sent. These humidifiers have a high airway resistance (resistance) and high compliance, which has a disturbing effect on the quality of the artificial respiration. In addition, these humidifying systems have a relatively long heat-up time, because the humidifier must first heat up the total amount of water present in the evaporator chamber before the humidifier can exert the desired humidifying output. This may take up to 30 minutes, and the humidifying output is reduced relatively greatly each time cold water is refilled, which is disadvantageous for the respiration therapy.
A humidifier of this type has become known from DE 198 08 590 C2 (corresponding to U.S. Pat. No. 6,102,037), where the dispensing of the amount of water, which depends on the tidal volume flow, with superheated steam is described. The drawback of this device is the necessary pump to dispense the amount of water. Thus, parts subject to wear are present, which must be replaced by the user at regular intervals.